Overview
Diamond Valley Lake is a roughly 4,500-acre off-stream reservoir in southwest Riverside County near Hemet, built by the Metropolitan Water District of Southern California and first filled in the early 2000s. With about 800,000 to 810,000 acre-feet of capacity, it nearly doubled Metropolitan's surface storage and serves as a major drought, peak-demand, and emergency reserve for the Southern California imported-water system.
The lake is about 4.5 miles long and 2 miles wide, with roughly 26 miles of shoreline and depths commonly cited near 250 feet at full pool (maximum elevation about 1,748 feet). Steep embankments, limited natural inflow, and surrounding multi-species reserve lands give it a deep, enclosed character unlike riverine Sierra reservoirs.
Recreation focuses on fishing, trails, and limited boating from the Diamond Valley Lake marina and visitor facilities. Anglers pursue largemouth bass, striped bass, and other warmwater species under regulations set by the California Department of Fish and Wildlife, and the lake draws Inland Empire and Southern California day-trippers.
Water levels are managed by Metropolitan as part of regional supply operations rather than a classic flood-control rule curve. Elevations rise and fall with State Water Project and Colorado River deliveries, drought withdrawals, and emergency needs, so monitoring current lake levels is important for ramp access, fishing, and shoreline use. Nearby Lake Perris is another key East Branch storage and recreation lake in the same Southern California system.
Current Conditions
Diamond Valley Lake is currently 1.32 feet above full pool and has fallen slightly over the past week.
- 7-day trendFallingLatest movement can differ from the seven-day trend.
- 7-day changeDown 0.33 ft
- 30-day changeDown 0.33 ft
- Drought conditionsAbnormally Dry
- Active advisories2 active (Advisory)
About This Lake
Learn how this lake is managed, what affects its water level, and where Lake Insights gets its data.
Diamond Valley Lake is a 4,500-acre reservoir on the State Water Project imports via the Inland Feeder and Eastside Pipeline (no natural inflow) managed by Metropolitan Water District of Southern California.